Electronic systems and circuits have made a significant contribution towards the advancement of modern society and are utilized in a number of applications to achieve advantageous results. Numerous electronic technologies such as digital computers, calculators, audio devices, video equipment, and telephone systems facilitate increased productivity and cost reduction in analyzing and communicating data, ideas and trends in most areas of business, science, education and entertainment. Frequently, these activities often involve the presentation of various graphics information on a display.
Graphics applications associated with the display presentations can have different characteristics and features. For example, graphics applications can have different processing requirements, different quality features, involve different levels of complexity, and so on. A system may include multiple graphics processing units and the graphics processing units can also have different processing capabilities and characteristics. In addition, control software and hardware for each processor may be entirely different (e.g., processors manufactured by different vendors, etc.)and not able to be controlled identically. Furthermore, displays typically can only handle input from one graphics processing unit at a time and often have particular interface requirements. For example, if signaling is not performed correctly damage to the panel may result, or the user may observe disturbing visual artifacts, or the panel controller may force a failsafe shutdown.
Displays typically have panel power sequencing specifications that indicate signal activation timing requirements. For example, the standards panel working group (SPWG) indicates general mechanical and interface specifications (e.g., SPWG spec, http://www.spwg.org) for displays used in note book computers. FIG. 1A is an exemplary timing diagram for one panel power sequence for a LCD power control signal (LCD_EN), active LVDS signals (LVDS) and a LCD backlight control (B/L). The timing requirements between the transitions in the signals are typically defined by the display manufacturer.